Water sterilizer



Nov. 10, 1936. 1 R. JEWELL WATER STERILIZER Original Filed Oct. 17, 1933ATTORNEYS.

Reissued Nov. 10, 1936 UNITED STATES PATENT OFFICE County,

Pa., assignor to American Sterilizer Company, Erie, Pa., a corporationof Pennsylvania Original No. 2,044,433, dated June 16, 1936, Serial No.693,942, October 17, 1933. Application for reissue July 23, 1936, SerialNo. 93,431

21 Claims.

It is necessary for many uses to sterilize water and also desirable withmost of such uses to filter the water. It has been the practice tofilter the water as it has been delivered to the sterilizing receptacleand then disconnect the filter from the receptacle so as to preventlater contamination of the water through leakage past the filter. Thesefilters become very much contaminated in their use even where replacedwithin practical limits and there is always some menace incident topossible leakage from such filters to the receptacle.

The present invention is designed to obviate this condition andcontemplates the automatic sterilizing of the filter as the water in thesterilizing receptacle is sterilized.

During the cooling or withdrawal of sterilized water it is necessary topermit the introduction of air to prevent the formation of a partialvacuum in the sterilizer chamber. Such vacuum, if permitted, wouldinterfere with or entirely prevent the withdrawal of the water from thesterilizing receptacle. Unless otherwise guarded against, a partialvacuum formed due to withdrawal of water would be compensated for by airentering through the draw-off valve. This air would carry with itbacteria laden dust and would thus contaminate the sterilized water. Itmay be brought about in two ways, one, during the .cooling of thesterilized water and consequent condensation of the steam above thewater. The other cause tending to produce a vacuum arises from thewithdrawal of the sterile water itself and the necessary compensationfor the displacement. This requires that provision be made for theintroduction of air during the entire operation of the sterilizer. Thepresent invention contemplates the introduction of air through an airfilter made sterile automatically with each heating of the sterilizingreceptacle to sterilize the water. Features and details of the inventionwill appear from the specification and claims.

A preferred embodiment of the invention is illustrated in theaccompanying drawing as follows:

Fig. 1 is a section on the line I-I in Fig. 3.

Fig. 2 is an elevation of one of the filter unit supporting plates.

Fig. 3 shows a front elevation of the sterilizer.

I marks the sterilizer receptacle, 2 a heating and cooling coil withinthe receptacle, 3 an inlet pipe for delivering water to the upper partof the receptacle, and 4 a filter case. The filter case has a dischargeextension 5 screwed into a fitting Ii. The inlet pipe 3 is secured inthe fitting 6 and thus connected with the filter. A door 1 is hinged tothe filter case at 8 and is provided with a screw 9 at its opposite sideby which the door may be closed with seating pressure. A gasket 9a isarranged between the door and the filter case. The door is provided witha transparent plate I0 forming a window by means of which the conditionof the filter may be observed.

Water is delivered to the filter case through a pipe II which is screwedinto an inlet extension I2 on the case. Water filter units I3, I4 and I5are arranged in the case. These units are secured between perforatedplates. The opposing perforated plates of units I 4 and I5 are carriedby a spacer ring I 6 having an opening I! to the inlet passage I2a.Opposing plates on the units I3 and I4 are carried by a spacer ring I8.The spacer ring I8 has a discharge passage I9 at the top. A perforatedplate is provided at the front of the unit I3 and water is admitted tothe space between the plate 20 and the front of the case by way of'apassage ZI and to the space between units I4 and I5 by way of passage I?leading from the inlet port I2a. Water is discharged from the passagesI9 and I9a by way of a passage 22 to the discharged extension 5. Thewater filter plates may contain any suitable water filtering material,usually a cellulose pulp. The water, therefore, as it is admitted passesthrough the three units and is filtered thereby in the usual manner. Anair filtering unit 23 has a perforated plate 24 over the water filterunit I5 and a rear plate 25. A filtering medium, preferably of metalwool is arranged between the perforated plate 24 and the plate 25. Aswater is admitted through the unit I5 it passes not only through thewater filtering medium, but the air filter as well, thus wetting the airfilter, the air filter material giving very little resistance to theflow of water. The several filter units and spacers are assembled andlocked in place with the closing of the door and the difi'erentfiltering units may be readily removed and replaced through the dooropening. The water supply is provided with an admission valve 26. Thisis formed with a body 21 having a diaphragm 28 with the. valve openingand surrounding seat 29. A valve head 30 operates on the seat and iscontrolled by a valve stem 3|. The valve has a discharge passage 32 intothe pipe II and a supply pipe 33 is connected with the inlet side of thevalve. The valve body has an extension 34 with a. valve opening thereinand surrounding seat 35. A valve head 36 operates on the seat and isurged to closing position by a spring 31. The valve head 36 has aforward extension 38 which leads through the valve opening in thediaphragm 28 and is adapted to be engaged by a forward projection 38a onthe head 38. The relation of the extension 38 and the projection 38 issuch that when the valve head 30 is closed the valve head 36 is opened,and on the other hand, when the valve head 30 is opened, the valve head36 is closed through the action of the spring.

The extension 34 is connected by a nipple 39 with a thermally actuatedvalve 48. This thermally actuated valve has the usual diaphragm M with avalve opening 42 controlled by a valve head 43 and the valve head isactuated by a thermal element 44. The valve is connected by a nipple 45with a drain fitting 46 which fitting leads to a sewer connection 41.

In the operation of the sterilizer, the control valve is opened,admitting water through the filter by way of the passages abovedescribed and the inlet 3. After the admission of the water theadmission valve is closed and this opens the drain valve having the head36. The water in the sterilizer is then brought to sterilizingtemperature by means of the coil 2 and as the steam forms in thesterilizer it passes down the inlet pipe 3 and through the filter platesby way of the pipe II and through the open drain valve to the thermalvalve and this in response to the action of the steam closes. Steam thenbuilds up in the sterilizer to sterilizing temperature and is held onthe filter plates during this operation. As soon as the steam is cut offthe coil 2 and the steam pressure is reduced the thermal valve finallycools and opens. This affords an air passage back through the waterfilter plates to the sterilizer receptacle, but, if the sterilizer is tobe used, as exemplified herein, to sterilize the water as well as theair, and a comparatively dense material is used for the primary waterfilter plates, and less dense material is supplied for a portion of thefilter through which the air is bypassed, the air admission thusprovided through the less dense material satisfies the conditions forthe ordinary discharge of the sterilizer receptacle, and comparativelylittle air will pass through the comparatively dense water plates.

In order to filter the air and permit its ready admission where thepressure is reduced in the sterilizer receptacle a pipe 48 leads fromthe upper part of the fitting 46. Air vents 48 are provided for theready admission of air to the upper part of the fitting. Drainage,however, is provided from the pipe 48 to the fitting and thence to thesewer connection 41. The pipe 48 leads to a chamber 50 in the case. Thechamber 50 is connected by a passage 5|, controlled by a check valve 52,with the air filter 23 and with any reduction of pressure in thereceptacle the check valve 52 opens and permits air to pass into the airfilter up through the air filtering material to the passage H11 andthence to the receptacle to compensate for any vacuum producingconditions.

It will be noted that the air filter is subjected to the sterilizingaction of steam sterilizing the water in the same manner as the waterfilter plates and on the other hand there is sufficient condensate, ormoisture left in the air filter to assure a retention of any dust thatmay be carried with the air.

It will be seen, therefore, that with this structure the apparatus as awhole, so far as the sterilizing of the filters and providing againstpossible contamination through leakage, is automatic. The operatorsimply opens the admission valve, fills the sterilizer, closes theadmission valve and subjects the sterilizer to the usual sterilizingtemperature. The drainage of the filter is accomplished with the closingof the admission valve through the opening of the drainage valve. Shouldthere be leakage of any consequence from the admission valve thisunsterile water would pass through the drainage connection and operatingupon the thermally actuated valve would cool it and open it so as toprovide an ample escape for the water. After the sterilizer is cooledand the thermal valve is normally opened any leakage from the admissionvalve has a direct outlet to the sewer connection. With each operation,therefore, all the filters are thoroughly sterilized. The air filter isfully wetted by steam, or condensation, so that with any indrawing ofair any contaminating dust is retained in the filter.

What I claim as new is 1. In a sterilizer, the combination of areceptacle; heating means for heating water in the receptacle tsteam-forming temperature; a water filter; a drain for the filter; meanssupplying Water to the receptacle through the filter and sterilizingsteam to the filter from the receptacle upon discharge of water from thefilter; and means controlling the drain to discharge the water from thefilter and close the drain against the discharge of steam.

2. In a sterilizer, the combination of a receptacle; a heating means forheating the water to a steam-forming temperature; an air filter; meanssupplying air to the receptacle through the filter and applyingsterilizing steam to the filter from the receptacle; and devices closingthe filter against the discharge of steam when filled from thereceptacle.

3. In a water sterilizer, the combination of a receptacle; a heatingmeans heating water therein to a steam-forming temperature; a waterfilter; an air filter; means supplying water and air to the receptaclethrough said filters and applying steam to said filters from thereceptacle; and means closing said filters against a discharge of steamwhen filled from the receptacle.

4. In a water sterilizer, the combination of a receptacle; heatingdevices heating water therein to a steam-forming temperature; an airfilter; means supplying air through the filter to the receptacle andsupplying sterilizing steam to the filter from the receptacle; and athermal valve controlling said means to introduce air during thedischarge of the receptacle and closing said means to trap steam in thefilter as steam is led to it from the receptacle.

5. In a water sterilizer, the combination of a receptacle; heatingdevices for heating water therein to a steam-forming temperature; awater filter; means controlling the fiow of water through the filter tothe receptacle and steam from the steam space of the receptacle to thefilter comprising a manually operated admission valve controlling thewater; and an automatic means controlling the filter to discharge thewater from the filter upon the closing of the controlling valve and toadmit to and retain in the filter steam produced in the receptacle.

6. In a water sterilizer, the combination of a receptacle; heatingdevices heating waterin said receptacle to a steam-forming temperature;a water filter; an air filter; means controlling a fiow of water and airthrough the filters to the receptacle and a discharge of water from thefilter and providing for the admission of steam from the steam space ofthe receptacle to the filters; and an automatic means controlling thefilters to hold in the filters steam produced in the (receptacle uponthe discharge of water from the 7. In a water sterilizer, thecombination of a water receptacle; means for heating water therein tosteam-forming temperature; a water filter;

'means between the filter and the receptacle discharging water from thefilter to the receptacle and providing for a flow of steam to the filterfrom the steam space of the receptacle; a water conduit leading to thefilter; an admission valve for closing the conduit; a drain dischargingthe water from the filter to permit an infiow of steam from the steamspace of the receptacle to the filter, and means for closing the drainagainst the escape of steam. I

8. In a water sterilizer, the combination of a water receptacle; meansfor heating the water therein to steam-forming temperature; a watersupply inlet leading to the receptacle; a water filter discharging tothe inlet; a water conduit leading to the filter; an admission valve inthe water receptacle; means for heating the water therein tosteam-forming temperature; a water supply inlet leading to thereceptacle; a water filter discharging to the inlet; a water conduitleading to the filter; an admission valve in the conduit; a draindischarging the filter and permitting an infiow of steam from thereceptacle; and thermally actuated means closing the drain.

10. In a Water sterilizer, the combination of a water receptacle; meansfor heating the water therein to steam forming temperature; a waterfilter comprising removable filter plates; means between the filter andthe receptacle discharging water from the filter to the receptacle andproviding for a flow of steam from the steam space of the receptacle tothe filter; a water conduit leading to the filter; an admission valvefor closing the conduit; a drain discharging the water from the filterto permit an inflow of steam from the steam space of the receptacle tothe filter; and means for closing the drain against the escape of steam.

11. In a water sterilizer, the combination of a water receptacle; meansfor heating water therein to steam forming temperature; a water filter,said filter comprising a case, a plurality of filter plates in the casewith spaces formed between said plates, said case having dischargepassages discharging and communicating with some of the spaces, andspaces on the opposite side of the filter plates communicating to aninlet passage in the filter case; means between the filter dischargepassages and receptacle discharging water from the filter to thereceptacle and providing for a fiow of steam from the steam space of thereceptacle to the filter; a water conduit leading to the inlet passagein the filter; an admission valve for closing the conduit; a drain fordischarging the filter and permitting an inflow of steam from the steamspace of the receptacle to the filter; and means for closing the drainagainst the escape of steam.

12. In a water sterilizer, the combination of a water receptacle; meansfor heating the water therein to steam forming temperature; a watersupply inlet leading to the receptacle; a water fil- 'a water filterplate in the case receiving water from the inlet passage at one side anddischarging to the discharge passage; an air filter in the casedischarging to the discharge passage in the case; an air inlet passageto the air filter; means for preventing a return fiow from the airfilter; a water conduit leading to the inlet passage in the case; anadmission valve inthe conduit;-a drain discharging the filter; and meansclosing the drain.

13. In a water sterilizer, the combination of a water receptacle; meansfor heating the water therein to steam-forming temperature; a watersupply'inlet leading to the receptacle; a water filter discharging tothe inlet, said filter comprising a case having a discharge passageleading to the inlet and inlet passages leading to the case; a waterfilter plate in the case receiving water from the inlet passage at oneside and discharging to the discharge passage; an air filter in the casedischarging to the discharge passage in the case, said air filter havingits medium wetted through the action of water and steam in the case; anair inlet passage to the airfilter; meansforpreventing a return fiowfrom the air filter; a water conduit leading to the inlet passage in thecase; an admission valve in the conduit; a drain discharging the filter;and means closing the drain.

14. In a water sterilizer, the combination of a water receptacle; meansfor heating the water therein to steam-forming temperature; a watersupply inlet leading to the receptacle; 9, water filter discharging tothe inlet, said filter comprising a case having a discharge passageleading to the inlet and inlet passages leading to the case; a waterfilter plate in the case receiving water from the inlet passage at oneside and discharging to the discharge passage; an air filterin the casedischarging to the discharge passage in the case, said filter comprisinga chamber bounded on one side by a water filter plate and containing afilter material; an air inlet leading to the filter remote from thedischarge passage; means for preventing a return flow from the airfilter; a water conduit leading to the inlet passage in the case; anadmission valve in the conduit; a drain discharging the filter; andmeans closing the drain.

15. In a water sterilizer, the combination of a water receptacle; meansfor heating the water therein to steam-forming temperature; a watersupply inlet leading to the receptacle; a Water filter discharging tothe inlet, said filter comprising a case having a discharge passageleading to the inlet and inlet passages leading to the case; a waterfilter plate in the case receiving water from the inlet passage at oneside and discharging to the discharge passage; an air filter in the casedischarging to the discharge passage in the case, said filter comprisinga chamber bounded on one side by a water filter plate and containingmetal wool as a filter material; an air inlet leading to the filterremote from the discharge passage; means for preventing a return fiowfrom the air filter; a water conduit leading to the inlet passage in thecase; an admission valvein the conduit; a drain discharging the filter;and means closing the drain.

16. In a water sterilizer, the combination of a water receptacle; meansfor heating .the water therein to steam-forming temperature; a watersupply inlet leading to the receptacle; a water filfilter plate in thecase receiving water from the case; an admission valvein'the conduit; adrain dlschargingithe filter; meansclosing the drain; l and a connectionleading from the non-return means to-the drain.

b having a discharge passage leading to the supply inlet and an inletpassage leading to the case;

water filter plates receiving water from" the inletpassage at one sideof the plates and discharging to the discharge passage from the oppositesides 26--sof-theplates; a door on the case through which the plates maybe removed; an air filter compris ing a chamber bounded at oneside by awater filter plate, said chamber discharging to the discharge passageand having an inlet passage with lilh'a non-return valve;filter-"material arranged in the chamber; a water conduit leading to theinlet passage in thecase; an admission valve in the conduit; a draindischarging the filter and permitting an inflow of steam from thereceptacle; aneansclosingvthe drain actuated with the admissicn valve;thermally actuated means-controlling the drain; and a connectionbetween-the nonreturn valve from the air filter to the drain.

18. In-a water sterilizer, the combination ofa w receptaclmheatingdevices heating water therein to--a steaming temperature; an air filter;means 17. In awater sterilizer,the combination ora wate'r receptacle;means heating the water therein to steam-forming temperaturera watersupply inlet leading to the receptacle; a water filter dis-- charging tothe inlet; said filter comprising a case ter discharging to the inlet,said filter comprising a case having a discharge passage leading to theinlet and inlet passages leading tothe case; a wa-- supplying airthrough the filter to the receptacle and supplying-moisture to thefilterthrough steam delivered to the filter from'the receptacle; and a valvemechanism controlling said means for the introduction oi! air andpreventing an unobstructed outflow of steam from the receptacle.

19. In a water sterilizer, the combination of a receptacle; heatingdevices heating water therein to a steaming temperature; an air filter;means supplying-air through the filter to the receptacle and supplyingmoisture'to the filter from steam from the receptacle; and a valvemechanism controlling said means fortheintroduction of air andpreventing an unobstructed outflow of steam from the receptacle, saidmechanism comprising a thermal valve in the path of the steam.

20. Ina water sterilizer, the combination of a receptacle; heatingdevices heating water therein to a steam-forming temperature; an airfilter; means supplying air through the filter to the receptacle andsupplying sterilizing steam to the filter from the-receptacle; and avalve mechanism controlling said means for the introduction of air andfor closing-said means to trap steam in the filter.

21.- In a water sterilizer, the combination of a receptacle; heatingdevices heating water therein to a steam-forming temperature; an airfilter; means supplying air through'the filter to the receptacle andsupplying sterilizing steam to the filter and supplying moisture to thefilter through steam delivered to the filter from the receptacle, saidmeans comprising two passages to the filter from the outer air; and avalve mechanism controlling-said means for the introduction of air andpreventing an unobstructed outflow of steam from the receptaclecomprising a thermal valve in one passage from the outer air and a checkvalve against outfiowin the other passage.

RAYMOND L. JEWELL.

